Where is the injector pump located on a 1999 dodge 3500 diesel?

On a 1999 Dodge 3500 with a Cummins 5.9L diesel engine (the most common engine in that year and model), the injector pump is located on the front of the engine, driven directly by the crankshaft. It's not a separate unit like in some other diesel systems; it's an inline pump. You'll see it nestled in the engine's valley, towards the front.